Multipurpose Evaporated Metal Film Resistors

Evaporated metal film resistors have been prepared on ceramic bases which have properties that compare favorably with wirewound resistors. These resistors have been tailor-made for several different types of application. A molded style is available for general purpose applications. A coated version in nine different wattage ratings is aimed at power resistor applications. For high-temperature or high-precision requirements, a special hermetically-sealed variety is undergoing field evaluation. Controlled resistance-temperature coefficients having positive, negative, or near-zero values can be obtained. These resistors have much lower inductance values than conventional wirewound resistors. In addition, they are smaller in size and have a weight advantage particularly for the higher resistance ranges. They offer potential advantages when used for miniaturization or airborne equipment. Performance characteristics for the various types are presented and compared to their wirewound analogs and the existing military specifications.